JP2011171134A - Manufacturing method of organic el display - Google Patents

Abstract

The present invention provides a method for manufacturing an organic EL display in which leakage current is not generated by a foreign substance attached to an organic layer, and an electrode or a sealing film is not damaged by the foreign substance.
A step of removing a foreign substance from the first organic layer by irradiating a laser on the foreign substance in the first organic layer and its surroundings when detecting the inclusion of the foreign substance in the first organic layer; The step of forming the second organic layer by re-applying the organic material to the region irradiated with the laser is sequentially performed, and then, the tip of the needle with only the tip portion exposed is brought close to the second organic layer. This can be solved by performing the sixth step of drying the second organic layer by heating the needle.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing an organic EL display. In particular, in the manufacture of an organic EL display, when a defect occurs due to foreign matter mixed in the organic layer, the method has a feature in a method of repairing the defect.

  In recent years, organic EL displays using organic electroluminescence elements are expected as next-generation flat display panels. Since the organic EL display is a self-luminous display, it has no viewing angle dependency and has characteristics of high contrast, thinness, and light weight. In addition, there is an advantage that a high luminance can be obtained with low power consumption, and a display with good recognition and responsiveness can be realized.

  The organic EL elements constituting the organic EL display are arranged on a glass substrate in a matrix. In each organic EL element, an anode and a cathode are disposed so as to sandwich an organic layer. The organic layer is formed of a light emitting layer containing phosphor molecules, a hole conductive thin film layer and an electron conductive thin film layer sandwiching the light emitting layer. When a voltage is applied between the anode and the cathode, holes are injected from the anode into the hole conductive thin film layer. Further, electrons are injected from the cathode into the electron conductive thin film layer. At this time, holes and electrons are combined in the light emitting layer, and the light emitting layer emits light. Moreover, the organic EL element is protected against the outside air by a protective layer.

  In the production of these organic EL displays, it is important to form a laminated film of a plurality of organic layers. This is because the stacked state of the organic layer greatly affects the light emission efficiency and power consumption of the organic EL display.

  Hereinafter, an example of a method for manufacturing an organic EL display will be described.

  The manufacturing method of the organic EL display is roughly divided into two methods depending on the organic material.

  For organic materials, materials with two structures, low molecular materials and polymer materials, are used, vapor deposition methods such as vacuum deposition are used for low molecular materials, and coating methods such as inkjet are applied for polymer materials. Often done.

  When a low molecular material is used, since the vacuum deposition method is used, it is necessary to form the organic material on the substrate by heating the low molecular material to a high temperature. At this time, the organic material needs to be formed on the substrate separately for each emission color. For this reason, only a necessary portion is deposited with a metal mask. At this time, the metal mask undergoes thermal expansion due to heat during vapor deposition and is deformed. In particular, as the substrate size increases, the deformation of the metal mask due to heat increases, so that the organic material is not deposited in a predetermined pattern with the mask, and unevenness may occur in the formed deposited film. Accordingly, it is relatively difficult to produce a large screen size organic EL display using a low molecular material.

  On the other hand, when a polymer material is used, a coating method such as ink jet can be used because the material itself can be dissolved with a solvent or the like. In the inkjet method, an organic material is continuously ejected to a predetermined place toward pixels formed in a matrix on a substrate while moving an inkjet nozzle relative to the substrate to form an organic layer. Is the method. Since the ink jet method can form an organic layer only at a predetermined location, a pattern can be formed on a large-sized substrate without masking. Therefore, when a polymer material is used as the organic material, it is generally advantageous for manufacturing an organic EL display having a large screen size.

  When the organic layer is formed by a coating method such as an ink jet method, foreign matter 15 may be mixed into the organic layer 12 surrounded by the bank 18 as shown in FIG. Since the ink jet method is a technique for discharging an organic material from a nozzle or the like, if foreign matter adheres to the nozzle for some reason, the foreign matter may fall during application of the organic material and be mixed into the organic layer. Or the foreign material which accumulates in the apparatus itself which implement | achieves the inkjet method diffuses, and this foreign material may mix in an organic layer. Furthermore, there are cases where foreign materials are mixed in the organic material itself, and there are cases where the organic material is applied while the foreign materials are mixed in the organic material and foreign materials are mixed into the organic layer.

  Also, it is difficult to completely remove foreign matter even in a dust-free environment such as a clean room. Especially in the manufacture of large-sized displays, the area where the organic layer is applied is widened. It is assumed that the probability of mixing increases.

  When a foreign substance is mixed in the organic layer, as shown in FIG. 4, when a voltage is applied between the anode 11 and the cathode 13, a current leaks (shorts) between the anode 11 and the cathode 13 through the foreign substance 15. End up. When the current leaks, the current flow through the organic layer 12 between the electrodes decreases, and the luminance of the light emitting layer in the entire pixel decreases. In some cases, only a leakage current due to a foreign substance flows between the electrodes and almost no current flows in the organic layer, and thus the entire pixel may not emit light. In addition, the codes | symbols 10 and 14 in FIG. 4 are a glass substrate and a protective layer, respectively.

  In addition, if foreign matter is mixed between the electrodes as described above, current leakage causes an increase in power consumption and a decrease in light emission efficiency. Alternatively, the electrode formed on the foreign material may be poorly formed due to the foreign material and become insulative around the foreign material, resulting in no light emission. Furthermore, it is conceivable that the protective layer formed on the foreign matter becomes poorly formed due to the foreign matter, and the protective performance is lowered, leading to the deterioration of the organic layer and the luminance of the light emitting layer.

  In general, a laser repair method as shown in FIG. 6 is known as a method for repairing a defect caused by foreign matter mixed in an organic layer.

  The laser repair method is a method of preventing current leakage due to foreign matter by irradiating the laser 16 from the laser oscillator 17 to the foreign matter 15 in the organic layer, thereby destroying or removing the foreign matter 15. is there. However, since the laser repair method irradiates a foreign object with a high-energy laser, the organic layer 12 around the laser-irradiated region may be damaged due to heat or the like in addition to the region irradiated with the laser. There are many. Therefore, the organic layer 12 in a region larger than necessary may be destroyed with respect to the region irradiated with the laser. Furthermore, the protective layer 14 protecting the organic layer 12 is destroyed by laser irradiation, and oxygen, moisture, and the like enter the organic layer 12 to deteriorate the light emitting layer, and dark spots are generated in the light emitting layer. is there.

  Several laser repair methods have been proposed in order to solve the problem when a foreign substance is mixed in the organic layer and a leakage current is generated, in which only the defective part is destroyed and the organic layer other than the defective part is not damaged. (For example, refer to Patent Document 1 and Patent Document 2).

  Patent Document 1 describes a method in which an electrode is removed by a laser in a band-like shape surrounding a foreign substance with respect to the foreign substance between the cathode and the anode. Since the electrode only around the foreign matter is removed by the laser, the laser does not directly hit the foreign matter, so that the foreign matter periphery can be insulated without damaging the foreign matter. As a result, in Patent Document 1, it is said that current leakage can be prevented. Patent Document 2 describes a method in which laser light is irradiated to an organic layer or an anode in a defective portion to cause multiphoton absorption only in the defective portion. As a result, damage to the region other than the defective portion can be reduced, the defective portion can be destroyed, and current leakage between the anode and the cathode through the defective portion can be suppressed.

  However, in the technique described in Patent Document 1, it is practically difficult to absorb the laser energy only in the electrode and remove only the electrode. Further, in order to remove the electrode, it is considered that damage is caused to the organic layer passing therethrough, the organic layer is deteriorated in a wide range, and the emission luminance is lowered. In addition, when there is a protective layer on the electrode, since the electrode is sandwiched between the organic layer and the protective layer, the electrode cannot be completely removed, and leakage may occur again due to electrode fragments.

  Moreover, in the technique described in Patent Document 2, as long as the organic layer is irradiated with a laser, the organic layer is greatly damaged, and the organic layer may be destroyed more than necessary. Alternatively, the foreign matter may be finely diffused by the laser, causing an increase in leakage current. In addition, when the organic layer is focused and irradiated with laser, the anode below the organic layer and the TFT may be damaged. Therefore, when this method is used, defects may increase. The laser repair method disclosed in Patent Document 1 and Patent Document 2 is a method of repairing a defective portion in a state where an electrode and a protective layer are formed after forming an organic layer to form a panel. When laser repair is used, it is difficult to completely repair defects, and in some cases, there is a possibility of increasing defects.

  In order to solve these problems, as shown in Patent Document 3, unlike the laser repair method, after forming the organic layer, the foreign matter mixed in the organic layer is detected, the foreign matter is removed by the laser, and the foreign matter is removed. There has been proposed a method in which an organic material is applied again to the removed organic layer portion to re-form the organic layer. In the case of this method, the foreign matter can be reliably removed and only the foreign matter can be irradiated with the laser, so that the foreign matter can be removed without damage to the periphery of the foreign matter. Therefore, by removing foreign matters mixed in the organic layer and re-forming the organic layer, it is possible to repair the defective portion without causing damage to others.

JP 2005-276600 A JP 2008-235178 A JP 2004-119243 A

  As described above, in the laser repair methods disclosed in Patent Document 1 and Patent Document 2, after forming an organic layer, an electrode and a protective layer are formed to repair a defective part in a panel state. For this reason, it is difficult to completely repair defects using laser repair.

  In the method described in Patent Document 3, the shape after coating is dried without control in the step of removing foreign matter with a laser and re-forming the organic layer (step of drying the re-coated organic material). Therefore, there is a problem that the shape of the re-applied organic layer cannot be formed smoothly. For this reason, the shape of the re-applied organic layer becomes uneven, and if a thin film such as an electrode is formed on this part, it becomes difficult to adhere the thin film closely and the resistance value increases when a current is passed. This leads to a decrease in luminance during light emission.

  In some cases, the thickness of the re-applied organic layer is thinner than the thickness of the other organic layers, and when current is passed through the organic layer, the current flows in a concentrated manner, causing an increase in power consumption. It can happen. In addition, after the solvent remains in the re-coated organic layer and the panel is formed, the solvent component evaporates over time, causing the organic layer to deteriorate, and the re-coated portion and its surroundings may not emit light. obtain.

  The present invention has been made in order to solve the above-mentioned problems, and foreign substances present in the organic layer are removed with a laser, and when the organic layer is formed again on the laser removal portion and repaired, the coating is reapplied. An object of the present invention is to provide an organic EL display manufacturing method capable of preventing and repairing defects caused by an organic layer.

In order to achieve the above object, a method for producing an organic EL display of the present invention comprises:
In a method of manufacturing an organic EL display including an organic layer sandwiched between a pair of electrodes on a substrate, a first step of forming a bank that defines the organic layer, and an organic material is applied to a region defined by the bank A second step of forming the first organic layer, and a third step of detecting contamination of foreign matter in the first organic layer after forming the first organic layer. If contamination of foreign matter is detected in the first organic layer in three steps, the foreign matter in the first organic layer and the foreign matter are removed from the first organic layer by irradiating laser around the foreign matter. A fourth step, and a fifth step of forming a second organic layer by re-coating an organic material in the region irradiated with the laser, and then the tip of the second organic layer The tip of the needle with only the part exposed, It is characterized in carrying out the sixth step of drying the second organic layer by heating.

  At this time, the material viscosity of the organic material reapplied in the fifth step is larger than the material viscosity of the first organic layer, and the first organic material is applied when the organic material is applied in the fifth step. It is good to apply without contact with the layer.

  In the present invention, the needle is disposed so as to be surrounded by a cooling block, a part of the tip of the needle is exposed from the cooling block, and the tip of the needle is provided close to the second organic layer. It is desirable to heat the needle.

  Moreover, in the said invention, the said needle | hook is arrange | positioned surrounded by piping, a part of the front-end | tip part is provided exposed from the said piping, and the said piping is provided on the opposite side to the side in which the said front-end | tip part is provided. It is desirable to heat the needle while evacuating the interior.

  Furthermore, in the present invention described above, at least two pipes adjacent to each other are provided, the needle is provided in one pipe, a part of the tip of the needle is exposed from the one pipe, and the one An inert gas is blown from one end of the pipe toward the tip of the needle, and the needle is heated while exhausting the other pipe toward the side opposite to the side where the tip is provided. It is desirable.

  As described above, according to the method for manufacturing an organic EL display of the present invention, when foreign matter is mixed in the organic layer, the foreign matter is detected, then the foreign matter is removed with a laser, and the portion removed by the laser is applied again. In some cases, the high-viscosity material is locally applied and only this portion is locally heated, so that the foreign matter-mixed portion can be completely repaired. Therefore, since the generated defect can be completely repaired in the manufacture of the organic EL display, it is possible to manufacture the organic EL display with a high yield.

Sectional drawing of the heating unit for heating a 2nd organic layer in Embodiment 1 of this invention Sectional drawing of the heating unit for heating a 2nd organic layer in Embodiment 2 of this invention. Sectional drawing of the heating unit for heating a 2nd organic layer in Embodiment 3 of this invention. Cross-sectional view of an organic EL element in which foreign matter is mixed in the first organic layer The perspective view of the organic EL element in which the foreign material of the 1st organic layer mixed The figure which shows the method of the laser repair of patent document 1 with respect to the organic layer in which the foreign material was mixed Perspective view after removing foreign matter with laser for organic EL element with foreign matter mixed in organic layer Perspective view after organic substance is applied locally again after removing foreign substance with laser for organic EL element mixed with foreign substance in organic layer Diagram showing the relationship between laser energy density and organic layer removal The figure which shows the manufacturing method of the organic electroluminescent display of this invention Sectional drawing when the second organic layer is spread and formed when the second organic layer is formed on the portion of the first organic layer from which the laser is removed Sectional drawing when the second organic layer is locally formed with respect to the portion of the first organic layer from which the laser is removed

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The organic EL display manufactured by the manufacturing method of the present invention has at least a substrate and organic EL elements arranged in a matrix on the substrate.

  The organic EL element has at least an anode disposed on a substrate, an organic layer disposed on the anode, and a cathode disposed on the organic layer. Further, the anode and the cathode may have a reverse structure. The organic layer includes at least an organic light emitting layer, but may further include a hole injection layer, a hole transport layer, an electron transport layer, and the like. Moreover, the organic EL element may have arbitrary components, such as a color filter and a sealing film.

As shown in the flowchart of FIG. 10, the manufacturing method of the organic EL display of the present invention is
1) a first step (S1) of forming a bank defining the first organic layer on the substrate so that the organic layer can be formed at a predetermined position on the substrate;
2) a second step (S2) for forming a first organic layer in a region defined by the bank formed in the first step;
3) a third step (S3) for detecting foreign matter mixed in the first organic layer formed in the second step;
4) A fourth step (S4) of irradiating the foreign matter detected in the third step with a laser around the foreign matter and the foreign matter to remove the foreign matter mixed in the first organic layer;
5) A fifth step (S5) of applying the second organic material only to the removed region to the region of the first organic layer removed by the laser in the fourth step;
6) A sixth step (S6) of locally heating only the second organic layer applied in the fifth step to form the second organic layer;
Manufactured by.

  In the first step, a bank defining the organic layer is formed on the substrate. Here, “to form a bank on a substrate” means not only to directly form a bank on a substrate but also to form a bank on another member (such as an anode) formed on the substrate. Including.

  The type of substrate is not particularly limited as long as it has insulating properties and has desired transparency and mechanical properties. In general, a glass plate or the like is often used. The substrate may be subjected to surface treatment such as plasma treatment or UV treatment. The size and shape of the organic EL element defined by the bank or the like can be freely set according to the desired characteristics (for example, the resolution of the display).

  The bank may define an organic layer for each organic EL element, or may define an area including a plurality of organic EL elements arranged in a line. The plurality of organic EL elements arranged in a line emit light of the same color (red, green or blue).

  The material of the bank is not particularly limited, but acrylic resin, polyimide resin, novolac type phenol resin, etc. are preferable from the viewpoint of insulation, organic solvent resistance, and process resistance (resistance to plasma treatment, etching treatment, and baking treatment). . The material of the bank may be a fluorine resin (acrylic fluorine resin or polyimide fluorine resin). The bank may be subjected to surface treatment such as plasma treatment or UV treatment, whereby the lyophilicity or liquid repellency of the bank surface can be adjusted.

  In the second step, the first organic layer is formed in a region defined by the bank formed in the first step. As a method for forming the first organic layer, an application method such as an inkjet method, a dispenser method, a roll coating method, a spray coating method, or a spin coating method can be applied. The type of organic material and solvent to be applied in the bank is freely selected according to the type of organic layer and desired characteristics. Examples of the organic material constituting the light emitting layer include polyfluorene-based polymer organic materials.

  The organic EL element is formed by laminating an electrode and a thin film of a first organic layer. The thickness of each thin film is controlled at a level of several n to several tens of nm. Even if the manufacturing environment is strictly controlled and the manufacturing equipment is sufficiently maintained, foreign matter from the inside of the device or from the manufacturing environment is mixed during the formation of the first organic layer, and this is a leakage current. It can be a factor of occurrence.

  In the third step, it is detected whether foreign matter is present in the organic layer formed in the second step.

  A method for detecting a foreign substance present in the organic layer is not particularly limited, and there are a method by an appearance inspection using a microscope, an image inspection method, a pattern inspection method, and the like. If a foreign substance is detected in the organic layer, the process proceeds to the fourth step, and the foreign substance is removed by a laser so that a leak current due to the foreign substance does not occur, thereby eliminating the cause of the leak.

  In the fourth step, the foreign matter in the organic layer detected in the third step and its periphery are irradiated with a laser, and the foreign matter is removed from the organic layer by laser ablation. Here, the phrase “irradiate the laser to the organic layer and its surroundings” means that the laser is focused on the organic layer and its surroundings.

  The type of the laser light source is not particularly limited, and is, for example, a flash lamp pumped Nd: YAG laser. When an Nd: YAG laser is used, the laser wavelength can be selected from 1064 nm (fundamental wavelength), 532 nm (second harmonic), 355 nm (third harmonic), and 266 nm (fourth harmonic).

  The wavelength of the laser applied to the organic layer on the outer periphery of the foreign matter is not particularly limited as long as it can be absorbed by the organic layer, but is preferably 1100 nm or less, and particularly preferably 400 nm or less. That is, in the case of the Nd: YAG laser, it is preferable to irradiate the third harmonic (355 nm) or the fourth harmonic (266 nm). This is because a smaller laser wavelength has a smaller influence on a layer (a substrate, an anode, another organic layer, or the like) under the first organic layer (see JP-A-2002-124380). The energy density of the laser irradiating the poorly formed portion is appropriately set depending on the material and thickness of the first organic layer.

  The laser irradiation area is preferably adjusted according to the size and shape of the foreign matter. The laser irradiation area is adjusted by controlling the opening area of the slit.

  FIG. 9 is a diagram showing the result of examining the relationship between the energy density of the laser and the amount by which a part of the organic layer has been removed by the laser as a preliminary experiment.

In this experiment, an organic light emitting layer (polyfluorene-based polymer organic material; film thickness: 140 nm) formed on a glass substrate was irradiated with a laser having a third harmonic (355 nm) wavelength at various energy densities. As a laser light source, QuickLase-50ST2 (YAG laser, manufactured by New Wave Research) was used. The irradiation area of the laser on the surface of the organic light emitting layer was 50 μm, and the pulse width was 3 to 5 nanoseconds. Laser irradiation was performed by a single shot. The data shown in FIG. 9 is a diagram showing the relationship between the laser irradiation energy density (0.09 to 0.24 J / cm ² ) and the removal amount (depth) of the organic layer. From this figure, it can be seen that the removal amount of the first organic layer can be adjusted at a level of several tens of nm by controlling the laser irradiation energy density.

  FIG. 7 is a perspective view showing a state after removing foreign matters mixed in the organic layer 12.

  As shown in the figure, it is necessary to completely remove the foreign matter from the organic layer 12 by adjusting the laser irradiation area according to the size of the foreign matter. When the foreign matter is removed by the laser, the foreign matter fragments and the organic layer fragments around the foreign matter diffuse around the laser irradiation portion, which may cause a defect again. Therefore, a dust collector or the like may be installed in the vicinity of the laser irradiation unit to collect foreign matter fragments or organic layer fragments. At this time, the energy irradiated by the laser needs to be set to be thinner than the thickness of the organic layer in order to suppress damage to the base. The required laser irradiation energy (laser power density) may be set based on the data of the laser energy density and the organic layer removal amount shown in FIG.

  In the fifth step, the organic material is again applied to the region of the organic layer removed by the laser in the fourth step. Since the region where the organic material is applied is only the region where the organic layer is removed, it is necessary to apply a very small amount of the organic material. Therefore, it is preferable to apply the organic material by a micro droplet transfer device using a needle.

  The micro droplet transfer device is a device that can transfer a very small amount of material onto the substrate by transferring the droplet attached to the tip of the needle with a fine diameter close to the substrate and transferring the droplet to the substrate in a non-contact manner. (For example, a needle dispenser of Applied Microsystem Co., Ltd.). As shown in FIG. 8, the organic material is again applied to the removal portion by the laser of the organic layer 12 to form the second organic layer 20. At this time, in order not to affect the organic layer by the organic material to be re-applied, apply the organic material locally only to the part removed by the laser and not apply to other places as much as possible. It is necessary to limit the application area.

  Therefore, after re-applying the organic material (the organic layer formed by the re-applied organic material is hereinafter referred to as “second organic layer 20”), the wetting and spreading of the organic material as shown in FIG. It is necessary to suppress. Therefore, the second organic layer 20 is an organic material having a high viscosity (for example, 30 mPa · s or more) as compared with the viscosity of the material of the organic layer 12 originally formed in the region defined by the bank 18. The organic material is applied. As a result, the wetting and spreading of the organic material is eliminated in the portion where the foreign matter is removed from the organic layer 12 as shown in FIG. In addition, the application shape of the organic material when reapplying is preferably circular. This is because heat is propagated radially when heating in the drying after coating.

  In the sixth step, only the portion where the organic material is re-applied in the fifth step is locally dried to form the second organic layer 20.

When the second organic layer 20 is dried and formed after re-coating the organic material, a method of heating the entire substrate in a heating furnace or the like is also conceivable, but in that case, the organic layer is damaged by heat. Therefore, there is a possibility that the organic layer is deteriorated and the light emission efficiency is lowered. Therefore, it is necessary to dry only the organic material to be recoated. As a method for locally heating the second organic layer 20, there is a heating method such as a CO ₂ laser, a spot lamp, or a micro hot air heater.

However, in the case of the CO ₂ laser, since the laser power is strong, there is a possibility that the organic layer may be destroyed when the organic layer of several to several tens of nm is irradiated with the laser. In addition, in a spot lamp and an ultra-small heater, local heating is possible, but the heating spot is in the millimeter level, and becomes large with respect to the application region (several tens of μm) of the organic material to be re-applied, The area other than the area where the organic material is applied is heated widely. For this reason, the deterioration region of the organic layer is widened, and the light emission efficiency around the portion where the second organic layer is formed may be reduced.

  Therefore, as a method of locally drying only the re-applied organic material, the tip is heated by winding a heating wire around a fine needle of several tens of μm, and the heated needle is brought close to the re-applied organic material, A method of heating and drying only the organic material may be applied (a specific configuration will be described later).

  Enclose the heated needle with a cooling block so that heat is not transmitted to areas other than the place where the re-applied organic material is located, expose only the tip, and bring only the tip of the needle closer to the re-applied portion of the organic material. The organic material is heated or a heated needle is passed through the pipe to expose only the tip of the pipe, and the pipe is heated while sucking air. Alternatively, a heated needle is passed through the piping, and the inert gas heated by flowing an inert gas with only the tip exposed is sprayed onto the re-applied organic material. At that time, a pipe for sucking the gas is installed next to the inert gas. At this time, the inert gas may be heated by spraying the inert gas heated by a needle heated only in a limited area and sprayed on the re-applied organic material and then heated.

  According to these methods, only the re-applied organic material can be heated and can be locally dried, so there is no influence of heat on places other than the applied organic material, so heat degradation due to heating is minimized. To the limit. In addition, when the viscosity is high, such as a high viscosity material, it is difficult to control the shape by heating, but if a local heating method using a needle heated by a heating wire is applied, the heating temperature of the needle, the size of the needle, etc. By changing the value, it is possible to control the heating of the re-applied organic material and to appropriately control the shape after the heating.

  As described above, in the present invention, when the organic layer has a defect such as a foreign substance, the foreign substance is removed with a laser, the organic material is re-applied to the laser removing portion, and the second organic layer is formed. When repairing, only the re-applied organic material can be heated while being locally controlled to form the second organic layer. As a result, there is no residual solvent in the second organic layer, and the second organic layer can be formed without unevenness by controlling the shape. It can be formed without. Therefore, according to the present invention, defects due to the foreign matter mixed in the organic layer can be completely repaired, so that leakage current due to the foreign matter can be reduced, emission darkening can be reduced, and power consumption can be reduced. An EL display can be manufactured with a high yield.

  Hereinafter, embodiments of the production method of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

(Embodiment 1)
When forming the second organic layer 20, after applying the re-applied organic material to the laser removal portion of the organic layer 12, the heated needle is surrounded by a cooling block, and only the tip portion is exposed, and only the tip portion of the needle is exposed. An example in which heating is performed close to the second organic layer 20 will be described.

  The manufacturing method of the organic EL display according to the first embodiment includes 1) a first step of forming a bank, 2) a second step of forming a first organic layer, and 3) in the first organic layer. A third step for detecting foreign matter mixed in, 4) a fourth step for removing foreign matter mixed in the first organic layer by a laser, and 5) removal by laser in the first organic layer. A fifth step of applying the second organic material only to the formed region, and 6) after applying the second organic material to the first organic material, heating only the second organic material, Forming an organic layer.

  In the first step, a line bank defining an organic layer is formed on a substrate. Next, in the second step, an organic layer is formed by applying a solution containing the first organic material to a region defined by the bank formed in the first step by a coating method such as an inkjet method. In the third step, foreign matter mixed in the first organic layer is detected by an image inspection machine.

  Hereinafter, the description will be continued assuming that foreign matter is detected in the organic layer.

  In the fourth step, the foreign matter detected in the third step and its surroundings are irradiated with a laser to remove the foreign matter from the organic layer. The irradiation energy density of the laser is adjusted so that the light emitting layer is not completely removed. In the fifth step, the organic material is re-applied only to the region of the organic layer removed in the fourth step using the microdroplet transfer device. In the sixth step, only the place where the organic material is re-applied is heated to form the second organic layer in the portion of the organic layer that has been laser-removed.

  The organic material is re-applied to the laser-removed portion of the organic layer, and then when the organic material is heated, an electrothermal power is wound around a fine needle, and the needle is heated to a predetermined temperature by a heating wire. . As for the heating temperature, a temperature necessary for heating the organic material is confirmed in advance, and the amount of current flowing to the heating wire is controlled so as to be the temperature. The heated needle is brought close to the vicinity of the recoated organic material, and the second organic layer is heated in a non-contact manner by heat conduction.

  At this time, as shown in FIG. 1, the needle 1 having a sharp tip is surrounded by the cooling block 4, only the tip of the needle 1 is exposed, and the tip of the needle 1 is brought close to the second organic layer 20, By heating the needle 1 from the power source 3 via the heating wire 2, heat from only the tip of the needle 1 is locally transmitted to the second organic layer 20 by thermal radiation or convection. As a result, since heat is hardly transmitted to places other than the place where the organic material is re-applied, damage to the organic layer 12 in the periphery where the organic material is applied can be suppressed. Moreover, since it can heat locally, adjusting temperature accurately, the shape of the 2nd organic layer 20 can be smoothly formed without an unevenness | corrugation.

  Therefore, there is no damage to others due to the formation of the second organic layer 20, and the electrode and the sealing film can be formed on the second organic layer 20 without any defects.

  As described above, when a foreign substance is mixed in the first organic layer, the second organic layer is controlled to be free from defects by removing it with a laser, applying a second organic material, and drying locally. Therefore, it is possible to produce an organic EL display free from defects due to foreign matter.

(Embodiment 2)
In this embodiment, when heating the organic material to be reapplied, the heated needle 1 is passed through the pipe, only the tip of the pipe is exposed, and the reapplied organic material is heated while inhaling the pipe. explain.

  Since the steps other than the sixth step are the same as those in the first embodiment, only the sixth step will be described here.

  In the sixth step, when heating the re-applied organic material, the heating wire 2 is wound around the fine needle 1 and the heating wire 2 is used to heat the needle 1 to a predetermined temperature. As shown in FIG. 2, the heated needle 1 is placed through a pipe 5 that is sufficiently larger than the diameter of the needle 1, and only the tip of the needle 1 is exposed from the tip of the pipe. The second organic layer 20 is formed by heating the tip of the needle 1 close to the re-applied organic material. In a direction opposite to the direction in which the tip of the needle 1 is exposed, a pump that sucks in the pipe is installed, and the reapplied organic material is heated while sucking in from the pipe at the tip of the needle 1. Since heating is performed while sucking air, diffusion of heat due to heat convection from the tip of the needle 1 is suppressed by sucking air, and only the re-applied organic material can be locally heated.

  As a result, since heat is hardly transmitted to places other than the place where the re-applied organic material is provided, damage to the organic layer in the periphery where the organic material is applied can be suppressed. Moreover, since it can heat locally, adjusting temperature accurately, the shape of a 2nd organic layer can be smoothly formed without an unevenness | corrugation. Therefore, there is no damage to the other by forming the second organic layer, and the electrode and the sealing film can be formed on the second organic layer without any defects.

  As described above, when a foreign substance is mixed in the first organic layer, the second organic layer is controlled to be free from defects by removing it with a laser, applying a second organic material, and drying locally. However, since it can be formed, an organic EL display free from defects due to foreign matters can be manufactured.

(Embodiment 3)
In the present embodiment, when heating the re-applied organic material, the heated needle 1 is passed through the pipe, only the tip of the needle 1 of the pipe is exposed, and the pipe that draws air next to the pipe through the needle 1 An example in which an inert gas such as nitrogen gas is blown out from a pipe passing through the needle 1 that has been installed and heated, and the organic material is heated while taking in air from a pipe installed next to the inert gas will be described.

  Since the steps other than the sixth step are the same as those in the first embodiment, only the sixth step will be described here.

  In the sixth step, when heating the re-applied organic material, the heating wire 2 is wound around the fine needle 1 and the heating wire 2 is used to heat the needle 1 to a predetermined temperature.

  As shown in FIG. 3, the heated needle 1 is installed through a pipe 8 that is sufficiently larger than the diameter of the needle, and only the tip of the needle 1 is exposed from the tip of the pipe. The tip of the needle 1 is heated close to the re-applied organic material. In a direction opposite to the direction in which the tip of the needle 1 is exposed, a gas pipe for blowing an inert gas such as nitrogen gas is installed in the pipe 8, and the organic gas is blown out toward the tip of the needle 1 while blowing the inert gas. Heat the material.

  Next to the pipe 8 through which the heated needle 1 is passed, a pipe 5 for taking in air is installed, and an inert gas is blown out from the pipe 5 through which the heated needle 1 is passed. Then, the organic material is heated. The heated needle 1 heats the inert gas, and the heated gas is sucked in by the adjacent pipe. Therefore, local convection is caused to the place where the re-applied organic material is provided. Since heating is performed, almost no heat is transmitted to places other than the place where the organic material is applied.

  As a result, the second organic layer can be formed without damage to the organic layer around the place where the re-applied organic material is provided. In addition, since the amount of the inert gas blown out and the amount of intake air can be locally heated while accurately adjusting the temperature, the shape of the second organic layer can be smoothly formed without unevenness.

  As described above, there is no damage due to the formation of the second organic layer, and the electrode and the sealing film can be formed on the second organic layer without any defects.

  The manufacturing method of the organic EL display according to the present invention is such that when foreign matter is mixed in the organic layer, the foreign matter is removed with a laser, and when the organic material is locally reapplied to the laser removal portion, the reapplied portion Can be dried locally by heating. Therefore, it is possible to repair only the place where the foreign material is present without affecting the region other than the region where the foreign material is present in the organic layer. Therefore, according to the present invention, in the manufacture of an organic EL display, it is possible to reduce the light emission darkening and reduce the power consumption by reducing the leakage current, and it is possible to manufacture the organic EL display with a high yield. .

  In addition to the method for manufacturing an organic EL display, the present invention can also be applied to applications for manufacturing devices that require locally controlled heating.

1 Needle 2 Heating wire 3 Power supply 4 Cooling block 5 (For intake) piping 6 Intake 7 Inert gas blowing 8 (For gas blowing) piping 10 Glass substrate 11 Electrode (anode)
12 Organic layer 13 Electrode (cathode)
DESCRIPTION OF SYMBOLS 14 Protective layer 15 Foreign material 16 Laser 17 Laser oscillator 18 Bank 19 Laser removal part 20 2nd organic layer

Claims (5)

In a method of manufacturing an organic EL display including an organic layer sandwiched between a pair of electrodes on a substrate,
Forming a bank defining the organic layer;
A second step of forming a first organic layer by applying an organic material to a region defined by the bank;
After forming the first organic layer, a third step of detecting contamination of foreign matter in the first organic layer,
When contamination of foreign matter is detected in the first organic layer in the third step,
A fourth step of removing the foreign matter from the first organic layer by irradiating a laser on the foreign matter in the first organic layer and its surroundings;
And a fifth step of forming a second organic layer by re-applying an organic material to the region irradiated with the laser,
Performing the sixth step of drying the second organic layer by bringing the tip of the needle, in which only the tip portion is exposed, close to the second organic layer and heating the needle;
A method for producing an organic EL display characterized by the above. The material viscosity of the organic material reapplied in the fifth step is larger than the material viscosity of the first organic layer, and when the organic material is applied in the fifth step, the material viscosity is higher than that of the first organic layer. The manufacturing method of the organic electroluminescent display of Claim 1 apply | coated by contact. The needle is disposed so as to be surrounded by a cooling block, and a part of the tip of the needle is provided to be exposed from the cooling block, and the needle is heated by bringing the tip of the needle close to the second organic layer. The manufacturing method of the organic electroluminescent display of Claim 1 or 2. The needle is disposed so as to be surrounded by a pipe, a part of its tip is provided exposed from the pipe, and the needle is exhausted from the pipe to the side opposite to the side where the tip is provided. The manufacturing method of the organic electroluminescent display of Claim 1 or 2 which heats. Having at least two adjacent pipes,
The needle is provided in one pipe, a part of the tip of the needle is exposed from the one pipe, and an inert gas is flowed from one end in the one pipe toward the tip of the needle. Blowing,
The method of manufacturing an organic EL display according to claim 1, wherein the needle is heated while exhausting the inside of the other pipe toward the side opposite to the side where the tip is provided.

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